1. Field of the Invention
The present disclosure generally relates to optics and, more particularly, to a wavefront aberration measuring method and a wavefront aberration measuring device that measure wavefront aberrations of optical systems. In particular, the wavefront aberration measuring method and the wavefront aberration measuring device may be used for detection of a manufacturing error of an optical system.
2. Description of the Related Art
The Shack-Hartmann method is known as a method of measuring a wavefront aberration of an optical system. The Shack-Hartmann method forms a plurality of spot images by causing light, which is transmitted through a test optical system, to be incident on a lenslet array, reconfigures a transmitted wavefront of the test optical system based on the positions of the plurality of spot images, and hence measures a wavefront aberration.
Referring to Japanese Patent Laid-Open No. 2005-98933, the focal length of a collimator lens is changed in accordance with the magnitude relationship between the F-number of the test optical system and the F-number of the collimator lens, to increase the spatial resolution of aberration measurement.
When the wavefront aberration of the optical system is measured by the Shack-Hartmann method, the measurement result of the wavefront aberration may be changed depending on an arrangement error of the optical system with respect to a measuring device, and hence the wavefront aberration of the optical system may not be correctly measured.